If the diagnosis code B1B02 (1st squib) or B1B06 (2nd squib) is set to SRS-ECU, be sure to diagnose the CAN bus line.

OPERATION

Only when the frontal impact exceeding the threshold is simultaneously detected (turned ON) by the front impact sensor as well as by the analogue G-sensor and safing G-sensor in SRS-ECU, the electric current is supplied from SRS-ECU to the driver’s air bag module (squib).

TROUBLE JUDGEMENT

The code is set when the open circuit occurs to the SRS-ECU driver’s air bag module (squib) circuit.

Do not insert a probe directly into the terminal from the connector front side as the connector contact pressure may be weakened.

Insert the resistor harness probe from the back of terminals Nos. 1 and 2 (1st squib) or Nos. 3 and 4 (2nd squib) of C-207 driver’s air bag module connector.(5)Connect the negative battery terminal.(6)

caution

At the diagnosis code B1B02 check, always the diagnosis code B1B06 is set. The diagnosis code B1B06 is set because the 2nd side terminal is disconnected at the time of inspection, but it does not indicate any abnormality. Also, at the time of diagnosis code B1B06 check, always the diagnosis code B1B02 is set because the 1st side terminals are disconnected.

Do not insert a probe directly into the terminal from the connector front side as the connector contact pressure may be weakened.

Insert the resistor harness probe from the back of C-208 harness side connector terminals Nos. 3 and 4 (1st squib) or Nos. 1 and 2 (2nd squib).(5)Connect the negative battery terminal.(6)

caution

At the diagnosis code B1B02 check, always the diagnosis code B1B06 is set. The diagnosis code B1B06 is set because the 2nd side terminal is disconnected at the time of inspection, but it does not indicate any abnormality. Also, at the time of diagnosis code B1B06 check, always the diagnosis code B1B02 is set because the 1st side terminals are disconnected.

Q.
Is the diagnosis code No. B1B02 or B1B06 set?

(1)Check that the negative battery terminal is disconnected. If the negative battery terminal is connected, disconnect it.

(2)While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever, and disconnect the C-122 SRS-ECU connector.(3)

caution

To release SRS-ECU connector short spring in the following operations, disconnect this clock spring connector, and keep the squib circuit shorted.

Disconnect the C-208 clock spring connector.

(4)

caution

The short spring may not be released due to the insufficient insertion. Therefore, insert the insulator for 4 mm or more.

Insert the insulator (width: 3 mm, thickness: 0.5 mm) such as cable tie between the terminals Nos. 5 and 6 (1st squib) and Nos. 9 and 10 (2nd squib), and then release the short spring.(5)

caution

Do not insert a probe directly into the terminal of C-208 harness side connector from the connector front side as the connector contact pressure may be weakened.

Take the measurements below at the C-122 and C-208 harness side connectors.